Sarah Silbiger/The New York Times

In 1992, before Bill Clinton became “our first black president,” before Newt Gingrich’s “Republican revolution,” before the advent of Barack Obama, I wrote a book about how race had come to dominate American politics.

I argued that the enactment of the Civil Rights Act of 1964

set in motion a realignment of the two parties. As whites began to feel the costs of the civil rights revolution — affirmative action, busing, urban violence — Republicans recognized the potential of race to catalytically interact with the broader rights revolution and the anti-tax movement to drive working and middle class voters out of the Democratic Party.

I also wrote about the political power of racial resentment:

Race gave new strength to themes that in the past had been secondary — themes always present in American politics, but which previously lacked, in themselves, mobilizing power. Race was central, Richard Nixon and key Republican strategists began to recognize, to the fundamental conservative strategy of establishing a new, noneconomic polarization of the electorate, a polarization isolating a liberal, activist, culturally permissive, rights-oriented and pro-black Democratic Party against those unwilling to pay the financial and social costs of this reconfigured social order.

The situation hasn’t changed much.

Heading into the 2020 election, President Trump is prepared for the second time in a row to run a racist campaign. He continues, for example, to denigrate, in virulent terms, immigrants from Mexico and Central America.

At the same time, Democrats are doubling down on a racially liberal political agenda, becoming more outspoken and more confrontational in their defense of diversity and multiculturalism. Two of the party’s top-tier candidates for president — Senator Cory Booker and Senator Kamala Harris — are African-American, one — Julián Castro — is Latino, and all of the current Democratic contenders unabashedly promote the rights of racial and ethnic minorities.

The continuing Democratic quandary is how to maximize essential minority turnout, and at the same time retain — or recruit — sufficient numbers of white working class voters to secure victory on Election Day.

My Times colleagues Jonathan Martin and Alexander Burns reported on Feb. 25 that Democratic operatives are debating whether the party should spend “time, money and psychic energy tailoring their message to a heavily white, rural and blue-collar part of the country” or focus instead on areas where “their coalition is increasingly made up of racial minorities and suburbanites.”

The dispute, according to Martin and Burns,

is not merely a tactical one — it goes to the heart of how Democrats envision themselves becoming a majority party. The question is whether that is accomplished through a focus on kitchen-table topics like health care and jobs, aimed at winning moderates and disaffected Trump voters, or by unapologetically elevating matters of race and identity, such as immigration, to mobilize young people and minorities with new fervor.

Poll data suggests that Trump is driving Democratic liberals further left and conservative Republicans further right on a key test of racial attitudes.

Michael Tesler, a political scientist at the University of California-Irvine and the author of the 2016 book “Post Racial or Most Racial,” writes in “Racial Attitudes and American Politics,” a chapter in a forthcoming book:

Democratic and Republican voters do not simply disagree about what the government should do on racially charged issues like immigration and affirmative action, they now inhabit increasingly separate realities about race in America.

The growing alignment between racial attitudes and public opinion, Tesler continues, “has polarized the electorate and helped make American politics increasingly vitriolic.”

Racial attitudes have, in turn, become indelibly linked to partisan identification and “party identification influences just about everything in contemporary American society,” Tesler writes:

Partisanship is not only the most important determinant of our vote choices and policy preferences, but it shapes countless other beliefs and behaviors. Party identification has even been linked to who we find attractive and who we decide to marry, how we perceive objective conditions like the unemployment rate and federal budget deficit, which neighborhoods we want to live in, and the type of TV shows and cars we like.

Because of this, Tesler argues, “the racialization of party identification is by itself the racialization of American politics and society.”

Ryan Enos, a Harvard political scientist notes that

The pull of racial attitudes seems to be moving both directions — so that racial conservatives are being drawn into the GOP and racial liberals are being drawn into the Democratic Party.

Political ideology, Enos continued in an email,

is a broad orientation that is influenced by basic psychological traits and these traits orient a person toward a particular worldview that can be ideologically conservative or liberal and also causes one to be more or less ethnocentric.

The growing linkage between ideological and ethnocentric views has, in turn, contributed to a striking development in congressional elections.

Stephen M. Utych, a political scientist at Boise State University, conducted a detailed analysis — “Man Bites Blue Dog: Are Moderates Really More Electable than Ideologues?” — of winners and losers in House races from 1980 to 2012.

Utych found that a core premise of both political operatives and political scientists — that “moderate candidates should be more electable in a general election than ideologically extreme candidates” — is no longer true.

In fact, in 2012, ideologically extreme candidates became more electable than moderates, as the accompanying graphic shows.

In 1980, at the start of the period Utych studied,

moderates were quite likely to win — very extreme candidates were less than 20 percent likely to win election in 1980, while ideologically moderate candidates were nearly 80 percent likely to win.

By 2008, however, Ultych…